The present invention relates in general to computer security devices and in particular to a system for preventing an unauthorized remote user from gaining access to a computer.
Remote terminals for providing access to digital computers have been used for many years. Typically, conventional telephone lines have been used to connect such remote terminals to the digital computers. A telephone number or other central switching number is utilized to select the particular circuit connected to the computer. Although steps are usually taken to maintain such telephone numbers secret, the numbers are often discovered and unauthorized access to the computer becomes a reality. Despite the fact that access codes are typically programmed into the computer to prevent the use thereof unless the proper access code is initially provided, such access codes can be discovered or defeated if an unauthorized user has access to the computer. Unauthorized use of the computer renders it vulnerable to damage or misuse and can cause proprietary information stored in the computer to be disclosed to unauthorized persons.